Fire alarm hook tripping mechanism



Jan. 18, 1944. C KOONTZ FIRE. ALARM HOOK DRIPPING MECHANISM Filed Oct. 16, 1941 2 Sheets-Sheet l F 9.11; G'harles EFoontz .ZNVENTOR.

ATTORNEYS a 1944- I c. E. KOONTZ 2,339,706

FIRE ALARM HOOK TRIPPING MECHANISM Filed Oct. 16, 1941 Z SheetS-Shget 2' (L'hiar Ze/s EKom i 2'2,

INVENTOR.

ATI'D R N EYE Patented Jan. 18, 1944 UNITED STATES PATENT OFFICE FIRE ALARM HOOK TRIPPIN G MECHANISM Claims.

This invention relates to fire alarm hook tripping mechanism and has for an object to provide a rotary spring pressed shaft on the outer face of the inner door of a fire alarm box, the shaft having a cam overlying the conventional hook which starts the spring motor mechanism for telegraphing the box call number to the fire department, the shaft having a crank at one end disposed in front of a spring pressed bolt on the inner face of the outer door of the box so that when the outer door is opened after breaking the conventional glass and turning the door lock handle, the rock shaft will be rocked and the cam thereof will push down the hook, automatically starting the time controlled telegraph mechanism of the box and dispensing with the usual procedure of the operator pulling down the hook after opening the outer door. of the box.

A further object is to provide mechanism of this character on which the spring pressed bolt on the inner face of the front door of the fire alarm box is controlled by a lock mechanism which may be key operated to retract the bolt laterally from the crank so that an inspector may insert his key and open the outer door of the fire alarm box without turning in an alarm.

A further object is to provide apparatus of this character which will be formed of a few strong, simple and durable parts, which will be inexpensive to manufacture, and which will not easily get out of order.

With the above and other objects in view the invention consists of certain novel details of construction and combinations of parts hereinafter fully described and claimed, it being understood that various modifications may be resorted to within the scope of the appended claims without departing from the spirit or sacrificing any of the advantages of the invention.

In the accompanying drawings forming a part of this specification:

Figure 1 is a fragmentary front elevation of a fire alarm box equipped with hook tripping mechanism in accordance with the invention, a portion of the outer door being broken away to expose the hook tripping mechanism.

Figure 2 is a cross sectional view taken on the line 22 of Figure 1 showing the hook tripping mechanism in top plan.

.Figure 3 is a vertical sectional view taken approximately on the line 3-3 of Figure 1.

Figure 4 is a detailed longitudinal sectional view, drawn to large scale showing the hook, the rock shaft and the cam in normal position.

Figure 5 is a view similar to Figure 4 but showing the cam and hook in position to actuate the spring motor box call number mechanism when the outer door is opened.

Figure 6 is a detailed cross sectional view taken on the line B-6 of Figure 1 showing the spring pressed bolt on the rear face of the outer door and the key operated lock mechanism associated with the bolt, the lock mechanism being shown locked in operative position by a plug removably fitted in the key slot of the lock barrel and interfitting the kerf in the barrel housing.

Figure 7 is a vertical sectional view'taken on the line T'! of Figure 6.

Figure 8 is a detailed front elevation of the lock for controlling the position of the spring pressed bolt, and showing the pivoted guard in released position to expose the lock.

Figure 9 is a detailed perspective view of the screw having a disk head for locking the guard in position to conceal the lock.

Figure 10 is a detailed perspective view of the plug for releasably holding the spring pressed bolt in operative position to actuate the rock shaft.

Figure 11 is a vertical sectional view taken on the line H-ll of Figure -1 showing the stop against which the crank of the rock shaft is held by the spring of the rock shaft.

Referring now to the drawings in which like characters of reference designate similar parts in the various views, It) designates a conventional fire alarm box having a hinged outer door H, a hinged inner door 12, time controlled call number telegraph mechanism l3, a hook l4 projecting through an opening H5 in the inner door and adapted to be pulled down manually when the outer door is opened, to start the mechanism l3, a housing I6 on the outer face of the outer door, a glass front wall I! for the housing, adapted to be manually broken to gain access to the handle 18 of a lock I 9 on the inner face of the outer door, having a spring pressed bolt 28 engaged back of the door jamb 2| of the outer door. These parts are conventional.

In carrying out the invention a base plate 22, of substantially rectangular contour, is secured to the front face of the inner door l2 by screws 23 and is provided with a circular opening 24 which registers with the conventional opening 15 in the inner door and permits the hook it to project forwardly beyond the base plate.

A rock shaft 25 is journaled in bearing brackets 25 which extend forwardly from the front face of the base plate. The rock shaft is provided at one end with a downwardly extending crank 21 and between the bearing brackets is provided with a cam in the nature of a curved plate 28 which is secured at one end to the rock shaft by screws 29 and at the free end overlies the hook I4, see Figure 4. The crank 21 normally held against a stop 9 in the nature of an angular member secured to the base plate by screws 8, see Figures 3 and 11, through the medium of a helical'spring I, see Figure 2;" which is secured at one end to a screw 6 which is threaded into the rock shaft, see Figure 1, the other end of the spring being secured to one of the screws 23 which mount the base plate on the inner door. When the crank 21 is rocked forwardly and upwardly the cam 28 will be rocked downwardly from the position shown in .Figure.

4 to the position shown in Figure and depress the hook 14 to start operation of the spring motor mechanism l3. f

The crank 2! is actuatedby, opening movement of the outer door lland for this purpose a spring pressed bolt 30 is mounted in an angular bracket 3|, see Figure 2, which is secured by screws 32 engaged in lugs 33 which project rearwardly from the inner faceof the. outer door I l. The spring pressed bolt is normally engaged in rear of the crank 21 so that whenthe outer door is opened thebolt will rock the crank to turn thecrank shaft and depressthe hook for actuating the spring motor mechanism;

The spring pressed bolt is normallyheld in operative position and for this,purpose a lock barrel 34, see Figures 6, 7 and 8, is mounted in an opening 35 in the outer door II and is provided with a key slot 36 to normally receive a flat finger 31 which projects from a plug 38 slideably fitted in the outer end of the opening 35 of the outer door, seeFigure '7. The. finger extends throu h the key slot and normally is engaged in a kerf '39 formed in the housing 40 of the barrel so that the finger prevents rotation of the barrel and consequently hold the spring pressed bolt 30 against movement, and in a position back of the crank 21. Consequently when the outer door is opened the spring pressed bolt will be carried forwardly by the door and rock the crank as heretofore described, to actuate the time controlled mechanism of the fire alarm box. v

It isdesirable that provision be made for opening the outer door without actuating the hook of the fire alarm box so that the spring motor mechanism may be wound periodically and inspection and repairs may be made. To accomplish this the plug 38 must be removed so that a suitable key carried by the inspector may' be inserted in the" key slot of the lock barrel 34 to tum'and withdraw the sprin pressed-bolt 30 laterally beyond the crank 21. When this is done the inspector may turn the handle 18 0f the lock l9of theouter'door H to retract the spring pressed bolt '20 and open the door, the spring pressed bolt 30 during such movement moving in a forward 'p'ath' outside of the crank 21 and not'di'sturbing the crank. f

To prevent tampering a fiat plate guard 4!. see Figure 8,:is provided with a'hinge ear 42 which receives a pivot pin 43 projecting forwardly from the outer face of the outer door N, there being a washer 44 disposed between the head of the pivot pin and the hinge ear. The guard normally conceals the lock barrel 34 and housing Mthereof, see Figure 1, but'may be swung upwardly to'the .position shown in Figure 8'. to'expose the lock barrel and plug. $38. T'Ih6 guard ing out the screw 45 and removing the screw bodily to permit the guard being swung up to released position shown in Figure 8 when it is desired to remove the plug 38 to permit insertion of the-inspectors key for operating the lock barrel to retract the spring pressed bolt 30 and permit opening of the outer door H Without tuming in an alarm, a heretofore described.

From the above description it is thought that the construction and operation of the invention will be, fully understood without further explanation".

' What is claimed is: Y

l. The combination with a fire alarm bo'x having arr-outer door, an inner door, a hook for starting the mechanism of the fire alarm box project ing through the opening in the inner door, of a shaft rotatably mounted on the front face of the inner door, a crank on the shaft, a cam on the shaft overlying the hook, a stop against which the crank abuts, a spring connected to the shaft for holding the crank in engagement with the stop and holding the cam spaced above the hook, and means carried by the inner side of the outer door disposed to extend between the crank and the inner door when the outer door' is'closed and to swing the crank and actuate the shaftfor depression of the hook when the said outer door is opened.

2. -.The combination with a fire alarm box having an outer door, an inner door, and a hook for starting the mechanism of the fire alarm box projecting through an opening in the inner door, cam. means mounted on the outer face of the inner door adapted to engage and depress the hook, a crank connected to said means for actuating the means, a spring pressed bolt on'the inner face of the outer door engaged between the crank and the inner door adapted to swing the crank when the outer door is opened and actuate the cam means, and means accessible for operation from the outside of the outer door for retracting the spring pressed bolt laterally from the crank to permit the outer door being opened without disturbing the position of the crank.

3. The structure as of claim 2 and in which the last named means comprises a key. operated lock associated. with the spring pressed bolt, adapted to be actuated from the outside of the outer door to retract the bolt.

4. The combination with a fire alarm box having an outer door, an inner door, a hook for starting the mechanismof .the fire alarm box pro jecting through an opening in the inner door, of means mounted on the outer face ofthe inner door adapted to engage and depress the hook, a crank connected to said means, a member carried by the rear face of the outer door and normally held between the crank and the inner door to swing the crank when the outer door is opened and actuate the first mentionedmeans to press downthe hook. for starting the mechanism of the fire alarm box, and a key operated means accessible for operation from the outside of the outer and holding the cam spaced above the hook, a sliding bolt carried by the rear face of the outer door and extending between the crank and the inner door to swing the crank when the door is opened and operate the shaft to cause the cam to depress the hook for starting the mechanism of th fire alarm box, and a key operated means accessible for operation from the outside of the outer door for sliding the bolt from the rear of 10 the crank.

CHARLES E. KOONTZ. 

